1. Field of the Invention
This invention relates to a liquid to pasty preparation of sodium hydrogen cyanamide and certain organic compounds in the form of a suspension. It may be used, inter alia, in the field of oxidative bleaching or as a starting material for chemical synthesis.
2. Discussion of Related Art
Sodium hydrogen cynamide, also known as monosodium cyanamide, is a salt of cyanamide having the formula NaHNCN. It is a colorless solid which is highly hygroscopic and which reacts quickly with the CO.sub.2 in the atmosphere. By virtue of its high reactivity to many groups of compounds, NaHNCN is a versatile reagent in chemical syntheses (for example, U.S. Pat. No. 4,595,782) and has also been used as an activator for hydrogen peroxide and derivatives thereof in bleaching processes (U.S. Pat. Nos. 4,025,453; 4,086,175 and 4,086,177).
NaHNCN generally accumulates during its production in the form of a fine powder which is characterized by high dust emission when dry and which, not least because of its sensitivity to CO.sub.2 and H.sub.2 O, is very difficult to handle and can only be accurately metered at considerable cost. Accordingly, there is a need for a form of NaHNCN which is easier to handle and which lends itself better to metering. In particular, there is a need for readily pumpable form of NaHNCN.
Attempts to use NaHNCN in solution failed because this salt, which for the most part is readily soluble only in water and lower alcohols, reacts more or less quickly with these solvents, decomposing in the process.
One possible alterative to using NaHNCN in solution is, in principle, to suspend the salt in liquids in which it is insoluble or only sparingly soluble. However, in this case, too, the high reactivity of the NaHNCN is an obstacle to the chemical stability of the preparations. In addition, suspensions are always likely to be affected by separation problems which, in general, can only be solved by addition of suspension stabilizers. However, the presence of auxiliaries such as these is undesirable for most applications of the preparations.